Members for use in the construction of structural framework



Feb. 6, 1962 E. W. GRABOWSKI MEMBERS FOR USE IN THE CONSTRUCTION OF STRUCTURAL FRAMEWORK l0 Sheets-Sheet 1 Filed Sept. 3, 1957 962 E. w. GRABOWSKI 3,019,866

MEMBERS FOR USE IN THE CONSTRUCTION OF STRUCTURAL FRAMEWORK Filed Sept. 5, 1957 10 Sheets-Sheet 2 Feb. 6, 1962 E. w. GRABOWSKI 3,019,866

MEMBERS FOR USE IN THE CONSTRUCTION OF STRUCTURAL FRAMEWORK Filed Sept. 5, 1957 10 Sheets-Sheet 3 QPYPQBB" FIG.6

COMO d E. w. GRABOWSKI 3,019,866

MEMBERS FOR USE IN THE CONSTRUCTION OF STRUCTURAL FRAMEWORK Feb. 6, 1962 10 Sheets-Sheet 4 Filed Sept. 3, 1957 E. W. GRABOWSKI Feb. 6, 1962 MEMBERS FOR USE IN THE CONSTRUCTION OF STRUCTURAL FRAMEWORK Filed Sept. 5, 1957 10 Sheets-Sheet 5 SOGQEQ (190% m YDOTYOGGS Feb. 6, 1962 E. w. GRABOWSKI 3,019,856

MEMBERS FOR USE IN THE CONSTRUCTION OF STRUCTURAL FRAMEWORK Filed Sept. 5, 1957 10 Sheets-Sheet 6 Feb. 6, 1962 E. w. GRABOWSKI MEMBERS FOR USE IN THE CONSTRUCTION OF STRUCTURAL FRAMEWORK 1O Sheets-Sheet 7 Filed Sept. 5, 1957 Feb. 6, 1962 E. w. GRABOWSKI MEMBERS FOR USE IN THE CONSTRUCTION OF STRUCTURAL FRAMEWORK l0 Sheets-Sheet 8 Filed Sept. 5, 1957 Feb. 6, 1962 E. w. GRABOWSKI MEMBERS FOR USE IN THE CONSTRUCTION OF STRUCTURAL FRAMEWORK l0 Sheets-Sheet 9 Filed Sept. 3, 1957 Feb. 6, 1962 E. w. GRABOWSKI 3,019,866

MEMBERS FOR USE IN THE CONSTRUCTION OF STRUCTURAL FRAMEWORK Filed Sept. 3, 1957 10 Sheets-Sheet 1O 3,019,866 MEMBERS FGR USE IN THE CONSTRUCTION OF STRUCTURAL FRAIVEWDRK Edward Witold Grabowski, Harrow-on-the-Hill, Eng

land, assignor to Metriframe Structures Limited, London, England, a British company Filed Sept. 3, 1957, Ser. No. 681,621 Claims priority, application Great Britain Sept. 3, 1956 Claims. (Cl. 189-46) This invention relates to improvements in members for use in the construction of structural frameworks and is particularly concerned with improvements in such members which may be of angle or channel section which are formed with a series of openings in at least two of the flanges of the member so that one or more of the openings may be utilised to bolt the member at a desired location to another member of a similar or different construction to form part of a framework.

According to the present invention in a member for use in the construction of structural frameworks and having at least two flanges with a common edge, one flange is provided with a first row of substantially circular apertures the centres of which lies substantially on a line parallel to said common edge and spaced therefrom, the centres of adjacent apertures being spaced a predetermined equal distance from each other, and theother flange is provided with second and third rows of substantially circular apertures the centres of the second row of which lie on a line parallel to the common edge and spaced from the outer face thereof by a distance substantially equal to the spacing of the centres of the apertures in said first row from said common edge, the centres of adjacent apertures in said second row being spaced from each other by said predetermined distance or an integral multiple thereof, and the centres of the third row of apertures lying on a line parallel to that of said second row of apertures and spaced therefrom on the side remote from said common edge by a distance substantially equal to the spacing of the centres of said second row of apertures from the outer face of said common edge, the centre of each aperture in said third row being arranged to lie on a line normal to said common edge and intersecting the centre of an aperture in said second row and the spacing between the centres. of adjacent apertures in said third row being the same as or an integral multiple of the spacing between the centres of adjacent apertures in said second row.

According to a preferred embodiment of the invention in a member having at least two flanges meeting at a common edge for use in the construction of structural frameworks, one flange is provided with a first row of substantially circular apertures the centres of which lie on a line parallel to the common edge of the flanges and spaced substantially equidistantly from the outer face of the common edge and the opposed parallel edge of the flange, the centres of adjacent apertures being spaced a predetermined equal distance from each other which distance is substantially equal to their spacing from the outer face of the common edge, a second row of substantially circular apertures is provided in the other flange with their centres lying on a line parallelto said common edge and spaced from the outer face thereof by said predetermined distance, the centres of adjacent apertures in said second row being spaced by said predetermined distance from each other and a third row of substantially circular apertures is provided in said other flange with their centres lying on a line parallel to said common edge and spaced from the outer face thereof by a distance substantially equal to twice said predetermined distance, the centres of adjacent apertures in said third row being spaced from nitcd States Patent 0 ice each other by a distance substantially equal to twice said predetermined distance and each lying on a line substantially normal to said common edge and intersecting the centre of an aperture in said second row.

Preferably every other aperture in said first row is of one size and the remaining apertures therein are of a larger size and all the apertures in said second row are of said one size whilst all the apertures in said third row are of said larger size.

Conveniently a fourth row of substantially circular apertures of said one size is provided in said other flange, the centres of the apertures in said fourth row lying on a line parallel to said common edge and spaced from the outer face thereof by a distance substantially equal to three times said predetermined distance, the centres of adjacent apertures in said fourth row being spaced from each other by a distance substantially equal to an even multiple of said predetermined distance and each lying on a line substantially normal to said commonedge and intersecting the centre of an aperture in said second row but not that of an aperture lying in said third row.

Advantageously the width of the outer face of said other flange in a direction normal to its direction of length is substantially equal to three times said predetermined distance where said other flange is provided with only said second and third rows of apertures and is substantially equal to four times said predetermined distance where the fourth row is provided. a

It is preferred to make the diameters of the apertures of said one size substantially equal to one half said predetermined distance and the diameters of the apertures of said larger size greater than one-half but not greater than two-thirds of said predetermined distance.

The invention also extends to the provision in combination with a member according to any one of the five immediately preceding paragraphs of an elongated rectangular member having a width substantially equal to twice said predetermined distance and formed with a row of substantially circular apertures the centres of which lie on a line spaced substantially equidistantly from the longitudinal edges of the elongated member and the centres of adjacent aperturesof which are spaced from each other by a distance corresponding to said predetermined distance multiplied by the square root of two. Where the apertures in the angle-section member are of two sizes, every other aperture in said elongated member is of said one size and the remaining apertures therein are of said larger size.

In order that the invention maybe clearly understood some embodiments thereof will now be described by way of example reference being made to the accompanying drawings in which:

FIG. 1 is a perspectiveview of an angle-section member according to the invention,

FIG. 2 is a view similar to FIG. 1 showing a modified angle-section member,

FIG. 3 is a transverse sectional view of a channel member according to the invention,

FIG. 4 is a developed plan view of the channel member shown in FIG. 3,

FIG. 5 is a transverse sectional view of a box-section member according to the invention,

FIG. 6 is a developed plan view of the box-section member shown in FIG. 5,

FIG. 7 is a transverse sectional view of a modified box-section member,

FIG. 8 is a developed plan view of the box-section member shown in FIG. 7,

FIG. 9 is a perspective view of a strip suitable for use with the angle-section, channel-section and box-section members of the preceding figures,

3 a FIG. is a perspective view of an angle-section membe: the two flanges of which are each similar to the strip shown in FIG. 9,

FIG. 11 is a fragmentary perspective view of a strip suitable for use with the angle-section, channel-section and box-section members illustrated in FIGS. 1 to 81 FIG. 12 is a fragmentary perspective view of an anglese'ction member having two flanges each similar to the strip of FIG. 11,

FIGS. 13, 14 and 15 illustrate how the angle-section member of FIG. 12 may be used with the angle-section members of FIG. 1 or 2,

FIG. 16 is a fragmentary perspective view showing how the angle-section member of FIG. 1 may be bolted to the angle-section member of FIG. 2 and the anglesection member of FIG. 10 with the members extending mutually at right-angles,

FIG. 17 is a view of FIG. 16 seen in the direction of the arrow Z, 4 I

FIG. 18 is a View of FIG. 16 seen in the direction of the arrow Y, a

FIG. 19 is a view of FIG. 16 seen in the direction of the arrow X, and

FIG. 20 is a fragmentary perspective view showing how the strip '17 of FIG. 9 may be secured to the angle section 1.

In the first example illustrated in FIG. 1 an anglesection member indicated generally at 1 for use in the construction of structural frameworks is formed of two flanges 2 and 3 which are substantially at right angles to each other the outer faces of which respectively have a Width of 2A and 3A where A is a predetermined distance. The narrower flange 2 is formed with a row of substan* tially circular apertures 4 the centres of which lie on a line B--B parallel to the common edge 5 of the section and spaced from the outer face thereof by a distance A so that this line B-B extends substantially mid-way along the length of the outer face of the narrower flange 2. The centres of adjacent apertures 4 are spaced from each other by a distance A and every other aperture 4 is of one size and the remainder are of a larger size. The smaller apertures have a diameter substantially equal to one half A and the larger apertures have a diameter not exceeding two-thirds A. The wider flange 3 is formed with two rows of substantially circular apertures 6 and 7 the centres of the apertures 6 in one row of which lie on a line C--C parallel to the common edge 5 of the section and spaced therefrom by a distance A and the centres of the apertures 7 in the other row of which lie on a line DD parallel to the common edge 5 of the section and spaced therefrom by a distance substantially equal to 2A. The spacing between the centres of adjacent apertures 6 is substantially equal to the distance A and these apertures each have a diameter substantially equal to one half A. The spacing between the centres of adjacent apertures 7 is substantially equal to the distance 2A and the diameters of these apertures is substantially equal to that of the larger apertures 4 in the flange 2.

The centres of the apertures 7 in the Wider flange 3 each lie on a line normal to the direction of length of' this flange which intersects the centre of a smaller aperture 6 in the adjacent row in this flange and the centre of each aperture 7 is contained in a plane containing the centres of an aperture 6 and a larger aperture 4 and extending transverse to the direction of length of the member 1. There is thus provided in the wider flange 3 at intervals along its length and in a direction normal thereto both a smaller aperture s and a larger aperture 7 the centres of which are spaced a distance A apart so that the narrower flange 2 of a similar angle-section member 1 having alternate large and small apertures 4 may readily be bolted thereto by means of these apertures with the two members 1 at right-angles to each other.

The angle-section member described above may be modified as shown in FIG. 2 to provide an angle-section member indicated generally at 3 by providing a third row of substantially circular apertures 9 in the wider flange 3 the centres of which third row of apertures 9 lie on a line E-E parallel to the common edge 5 and spaced therefrom by a distance substantially equal to 3A, the centres of adjacent apertures 9 being spaced from each other by an even multiple of the distance A and in this example by a distance substantially equal to 4A. In this case the width of the flange 3 is increased to accommodate the row of apertures 9 but is preferably not greater than 4A. The diameter of the apertures 9 in the third row is substantially equal to /2A.

It will be appreciated that two angle-section members 1 such as illustrated in FIG. 1 may be secured together to make a channel member by overlapping the wider flanges 3 with the apertures 7 in one flange 3 and the apertures 7 in the other flange 3 in register and passing bolts through two or more of the pairs of apertures 7 in register, the two narrow flanges 2 being disposed parallel to and spaced from each other. Where many such channel members are required it is wasteful of material to secure two angle-section members 1 together and conveniently the channel member is made in one piece as is illustrated at 10 in FIGS. 3 and 4, FIG. 4 being a developed view of the member shown in FIG. 3. The reference numerals used correspond to those used in relation to FIG. 1. It will be appreciated that the centres of the narrower apertures 6 are spaced a distance substantially equal to A from the adjacent common edge 5 and the centres of the larger apertures 7 are spaced a distance substantially equal to 2A from each common edge 5.

FIGS. 5 and 6 illustrate a substantially but not completely closed box-section member indicated generally at 11. This box section member 11 is similar in many respects to the channel sectional member 10 illustrated in FIGS. 3 and 4 and like reference numerals are used to indicate like parts. In this case however the width of the narrower flanges 2 is increased to a width substantially equal to 3A and a further row of apertures 12 is formed in each flange 2, these apertures having their centres lying on a line FF parallel to the line BB on which the centres of the apertures 4 lie and spaced therefrom by a distance substantially equal to A. In this case the apertures 4 are all of the smaller size i.e. they all have a diameter substantially equal to /2A and the apertures 12 are of the larger size the spacing between centres of adjacent apertures 12 being substantially equal to 2A and the centre of each aperture 12 lying on a line normal to the adjacent common edge 5 and passing through the centre of an aperture 4 in the same flange 2. Additionally an inturned flange 13 is provided on each flange 2 extending parallel to the common flange 3, the width of these flanges 13 being such that the free edges thereof do not meet or overlap. The inturned flanges 13 are each formed with a row of apertures 14 the centres of which lie on a line G.--G (FIG. 6) parallel to the adjacent edge 15 common to the respective flanges 13 and 2 and spaced therefrom by a distance substantially equal to A. The centres of adjacent apertures 14 are spaced from each other by a distance substantially equal to A and every other aperture 14 in a row is of the smaller size, i.e. has a diameter substantially equal to /2A and the remaining apertures 14 are of the larger size, i.e. have a diameter greater than /2A but not greater than twothirds A.

FIGS. 7 and 8 illustrate a modification of the box-like member 11 shown in FIGS. 5 and 6. This box-like member indicated generally at 16 is very similar to that illustrated in FIGS. 5 and 6 and like reference numerals are used to denote like parts. In this case however the width of the flange 3 common to the flanges 2 is increased to substantially 5A and a further row of apertures 7 is provided. The flange 3 is thus formed with two outer rows of apertures 6 all of a diameter substantially equal to /2A and two inner rows of apertures 7 all of the The centres of the apertures 7 in each row distance substantially equal to A from each other and the centres of adjacent apertures 7 in each row are spaced a distance substantially equal to 2A from each other, the centres of an aperture 7 in each row thereof lying on a common line normal to the common edges and passing through the centre of an aperture 6 in each row thereof. FIG. 9 illustrates an elongated member or strip 17 which may be used advantageously in combination with angle-section members such as illustrated in FIG. 1 or 2, channel-section members such as illustrated in FIGS. 3 and 4 or box-section members such as illustrated in FIGS. 5 and 6 or FIGS. 7 and 8 in the construction of structural frame works. The strip has a width not greater than 2A but not less than 1%A and is formed with a row of apertures 18 the centres of which lie on a line parallel to the longer sides of the strip and substantially equidistant from each of such sides. The centres or adjacent apertures 18 are spaced a distance from each other substantially equal to A and every other aperture is of the smaller size, i.e. has a diameter substantially equal to AA, and the remaining apertures 18 are of the larger size, i.e. have a diameter greater than /2A but not greater than two-thirds A. 7 Such a strip 17 may be secured, for example, as illustrated in PEG. 20 of the drawings, to an angle-section member 1 by laying at least a part of it over the flange 2 with the smaller apertures 18 in register with the smaller apertures 4 and the larger apertures 18 in register with the larger apertures 4 and passing bolts of appropriate size through two or more pairs of apertures in register. It may also be secured to the angle-section member 1 by arranging it to extend in a direction substantially normal to the common edge 5 of the member 1 with one of the smaller apertures 18 in register with an aperture 6 in the flange 3 and a larger aperture 18 in register with an aperture 7 and passing bolts of the appropriate size through the two pairs of apertures in register. Where greater strength is required an anglesection member 19 may be provided as shown in FIG. 10, the two flanges 2t and 21 of which are similar to the strip 17 of FIG. 9 but in this case it is preferred that the apertures 18 in one of the flanges 2t? and 21 shall have their centres on a line spaced a distance A from the common edge whilst the centres of the apertures 13 in the other flange lie on a line spaced from the common edge by a distance equal to A less the thickness of the material.

The invention also extends to the provision in combination with the angle-section. members, channel-section members and box-section members described above of an elongated rectangular member or strip 22 (FIG. 11) of a width not greater than 2A and not less than 1%A provided with a row of substantially circular apertures 23 the centres of which lie on a line substantially equidistantly spaced from the longitudinal edges thereof. Every other aperture 23 in this row has a diameter of substantially /2A and the remaining apertures in this row have a diameter larger than /2A but not exceeding two-thirds A and the centres of adjacent apertures 23 in this row are spaced from each other by a distance substantially equal to A times the square root of two. Where greater strength is required an anglesection member 24 (FIG. 12) may be provided having each flan e similar to the strip 22.

It will be appreciated that in the angle-section members, the channel-section members and box-section members described above there is provided in at least one flange thereof a row of smaller apertures and an adjacent row of larger apertures with the center of each larger aperture spaced from the centre of a smaller aperture in the adjacent row by a distance substantially equal to A times the square rootof two in a direction inclined at 45 to the direction of length of the member. Thus, for example, the centres of the apertures 7 in the flange 3 of the member 1 (FIG. 1) and the member 8 (FIG. 2) are spaced a distance equal to A times the square root of two in a direction inclined at 45 to the common edge 5 from the centre of an aperture 6 in the adjacent row of apertures. The centres of the smaller apertures 9 in the flange 3 of the member 8 (FIG. 2) are similarly spaced from the centres of the apertures 7 in the adjacent row. It will be seen that an elongated rectangular member or strip 22 (FIG. 11) or an angle-section member 24 (FIG. 12) may be bolted readily to the member 1 (FIG. 1), the member 8 (FIG. 2), the channel-section member 16 (FIGS. 3 and 4), the box-section member 11. (FIGS. 5 and 6), or the box-section member 16 (FIGS. 7 and 8) to extend at an angle of 45 to the direction of length ofsuch member.

.It will be seen that the angle-section members, channel-section members, and box-section members described above may be readily used to. construct frameworks in which the members ,areat right angles to each other and the provision of the elongated member or strip 22 (FIG. 11) or the angle-section member 24 (FIG. 12) enables these members 22 or 24 to be bolted into the structure at 45 to the other members to provide stays and struts.

Some examples of how thi may be done are illustrated in FIGS. 13 to 14. In FIG. 13 two angle-section members 1 are bolted together at right-angles to each other by overlapping the one ends of the wider flanges 3 of the two members with the two narrower flanges 2 extending in the same direction. The end-most apertures 6 in each of thewider flanges 3 are in register and similarly the end-most apertures 7 in each wider flange 7 are in register and bolts 25 and 26 of the appropriate size are passed through these apertures in register and a nut (not shown) screwed thereon. If desired washers such as shown at 27 may also be used. :Additionally an anglesection member 24 is disposed with one flange against the wider flanges 3 on the side remote from the narrower flanges 2 and extends at 45 to the direction of length of both members 1. As the length of the member 24 required to span the members 1 is proportional to the square root of the length of the members 1 measured from the ends thereof joined together and the location at which the member 24 is to be secured thereto and thecentres of the apertures 6 in the members 1 are spaced apart a istance A and the centres of the apertures 7 are spaced apart a distapce 2A whilst the centres of the apertures 23 in the member 24 are spaced apart a distance equal to A times the square root of two, it will be seen that there is no difficulty in arranging the member 24 relative to the members 1 so that adjacent smaller and larger apertures 23 in the member 24 register with apertures 6 and 7 in each of the members 1. Bolts 28 and 29 of appropriate size are passed through the apertures in register and nuts screwed thereon to provide a rigid framework. The bolts 25, 26 and 28 and 29 are of a size appropriate to the circular apertures through which they extend so that they are virtually in bearing in such apertures and so increase the strength of the framework as compared with frameworks formed from slotted members in which the members are held by friction between the respective members and the bOlts urging them together.

FIG. 14 illustrates how two members 1 may be joined by their narrower flanges 2 and by an angle-section member 24 secured to their narrower flanges 2. An additional angle-section member 24is provided to increase the rigidity of the framework.

FIG. 15 is similar to FIG. 13 but illustrates how two members 8 may be secured together at right-angles to each other by their wider flanges 3==and joined by an '3' angle-section member 24. It will be seen that in this case the members 8 are secured together at their one ends by four bolts St in bearing in the apertures and the member 24 is secured to each member 8 by three bolts 31 in bearing.

FIGS. 16 to 19 illustrate how a member 8 may be secured to a member 19 and a member 1 with the members extending mutually at right-angles. The member 1? isarranged to extend at right angles to the member 8 with itsflange 20 against the flange 3 of the member 8 and with two of the smaller apertures 13 in register respectively with an aperture 6 and an aperture 9 in the flange 3 of the member 8, bolts 32 being passed through these apertures in register to secure the members 8 and 19 together, these bolts 32 being in hearing. The member 1 is arranged to extend mutually at right-angles to the members 8 and 19 with its narrower flange 2 against the underside of the flange 21 of the member 19 and its broader flange 3 against the narrower flange 2 of the member 8. One of the smaller apertures 4 in the flange 2 of the member 1 is arranged in register with one of the smaller apertures 18 in the flange 21 of the member 19 and a bolt 33 is passed through these apertures so as to be in bearing therein and is secured. This secures the member 1 to the member 15 One of the apertures 6 of the member 1 is in register with one of the smaller apertures 4 in the member 8 and a bolt 34 is passed through these apertures in register so as to be in bearing therein and is secured, thereby securing the member 1 to the member 8. The members 1, 8 and 19 are thus rigidly secured together.

It will be appreciated that the members and strips described above may be combined in many different ways to provide frameworks of suitable shape and strength. The frameworks produced from the members and strips are easy to design by virtue of the pattern of the apertures and are capable of bearing relatively heavy loads. The stress or strain distribution pattern produced in the members or strips under load or tension is more regular than that produced in similar members having slots formed therein so that the members or strips are capable of with standing heavier loads than similar slotted members. Additionally the fact that the bolts used to connect the members and/ or strips are in bearing within the apertures through which they extend further increases the strength of the frameworks produced from members or strips ac cording to the present invention as compared with similar members provided with slots as in the latter case the slotted members are largely secured together by frictional engagement produced by bolts passing through the slots and urging the slotted members together.

It is preferred that the members of strips according to this invention should be produced from cold-rolled steel although hot-rolled steel may also be used.

The thickness of the members and strips is preferably etween 2 to 3 mm. dependent upon the load for which they are designed and the distance A referred to above is advantageously 2-0 mm., the diameter of the smaller apertures being 10 mm. and the diameter of the larger apertures being 11.5 mm.

It will be appreciated that certain tolerances must be allowed in the manufacture of members in accordance with the invention. Thus where a member has two flanges which meet at a common edge and one or both flanges have a row of apertures the centres of which lie on a line spaced from the common edge, this line is described above as being spaced a distance A from the outside of the common edge. It is essential that this spacing should not exceed A and it is desirable to allow for manufacturing tolerance that the distance should be slightly less than A. Thus where A is 20 mm. this distance is conveniently designed to be 19.5 mm. so that in the final product it does not exceed 20 mm. whilst at the same time retaining the maximum amount of metal between the peripheries of the apertures and the common edge.

It is preferred that the thickness of the flangesof the members and strips described above should be not less than 10% and not more than 15% of the predetermined distance A.

What I claim is:

1. A substantially box-section member comprising a longitudinally extending first flange having a width substantially equal to four times a predetermined distance and formed with three rows of substantially circular apertures having their centres on lines spaced from each other by said predetermined distance, the centres of the apertures in the two outer rows being spaced from the adjacent longitudinal edge of said first flange by a distance substantially equal to said predetermined distance and the centres of adjacent apertures in each of said outer rows being spaced from each other by a distance substantially equal to said predetermined distance and the apertures in said outer rows being of one size and having a diameter substantially equal to one-half said predetermined distance, the centres of adjacent apertures in the inner row being spaced from each other by a distance substantially equal to twice said predetermined distance and the apertures in the inner row being of a larger size and having a diameter greater than one-half said predetermined distance and not greater than twothirds said predetermined distance, longitudinally extending second and third flanges integrally joined to the respective longitudinal edges of the first flange and extending substantially normal to the latter both in the same direction, the second and third flanges having a width substantially equal to three times said predetermined distance and being each formed with two rows of substantially circular apertures, the centres of the apertures in one row of which lie on a line spaced from the adjacent longitudinal edge of the first flange by a distance substantially equal to said predetermined distance and the centres of adjacent apertures in this row being spaced apart by a distance substantially equal to said predetermined distance, these apertures being of said one size and the centres of the apertures in the other row of which lie on a line spaced from. the adjacent longitudinal edge of the first flange by a distance substantially equal to twice said predetermined distance, the centres of adjacent apertures in this row being spaced from each other by a distance substantially equal to twice said predetermined distance, these apertures being of the larger size, and an inturned flange formed on each of the second and third flanges and extending substantially normal to the latter and towards each other substantially parallel to said one flange, each inturned flange being provided with a row of substantially circular apertures every other one of which in a row is of said one size and the remainder thereof being of said larger size, the centres of the apertures in a row in each inturned flange lying on a line parallel to the adjacent longitudinal edge of the second or third flange and spaced therefrom by a distance substantially equal to said predetermined distance and the spacing between the centres of adjacent apertures in these rows being substantially equal to said predetermined distance.

2. A member for use in the construction of structural frameworks and having at least two flanges with a common edge wherein one flange is formed with a first row of substantially circular apertures the centres of adjacent apertures of which are spaced a predetermined equal distance from each other and lie substantially on a line parallel to saidcommon edge and spaced therefrom and from the opposed parallel edge of said one flange by a distance substantially equal to said predetermined distance, and the other flange is provided with second and third rows of substantially circular apertures the centres of adjacent apertures of the second row of which are spaced by said predetermined distance from each other and lie on a line parallel to said common edge and spaced therefrom by said predetermined distance, and the centres of adjacent apertures of the third row thereof are spaced from each other by a distance substantially equal to twice the distance between the centres of adjacent apertures in said second row and lie on a line parallel to said common edge and spaced therefrom by a distance substantially equal to twice said predetermined distance, the centre of each aperture in the third row being arranged to lie on a line normal to said common edge and intersecting the centre of an aperture in said second row, and every other aperture in said first row is of one size and the remaining apertures in said first row are of a larger size, all the apertures in said second row are of said one size and all the apertures in said third row are of said larger size, and all the apertures of said one size have a diameter substantially equal to one-half said predetermined distance and all the apertures of said larger size have a diameter greater than one-half said predetermined distance but not greater than two-thirds of said predetermined distance.

3. A member according to claim 2 wherein "a fourth row of substantially circular apertures is formed in said other flange, the centres of adjacent apertures in said fourth row being spaced from each other by a distance substantially equal to twice the distance between adjacent apertures in said third row and lying on a line parallel to said common edge and spaced therefrom by a distance substantially equal to three times said predetermined distance, each centre of an aperture in said fourth row lying on a line substantially normal to said common edge and intersecting the centre of an aperture in said second row but not that of an aperture lying in said third row.

4. A structural framework including, in combination, a member having at least two flanges with a common edge wherein one flange is formed with a first row of substantially circular apertures every other aperture of which is of one size and the remaining apertures of which are of a larger size and the centres of adjacent "apertures of which are spaced a predetermined equal distance from each other and lie substantially on a line parallel to said common edge and spaced therefrom and from the opposed parallel edge of said one flange by 'a distance substantially equal to said predetermined distance, and the other flange is provided with second and third rows of substantially circular apertures, all the apertures in said second row being of said one size and all the apertures in said third row being of said larger size, the centres of adjacent apertures of said second row being spaced by said predetermined distance from each other and lying on a line parallel, to said common edge and spaced therefrom by said predetermined distance, and the centres of adjacent apertures of said third row being spaced from each other by a distance substantially equal to twice the distance between the centres of adjacent apertures in said second row and lying on a line parallel to said common edge and spaced therefrom by a distance substantially equal to twice said predetermined distance, the centre of each aperture in said third row lying on a line normal to said common edge and intersecting the centre of an aperture in said second row, and an elongatedstrip element having a thickness not less than 10% and not greater than of said predetermined distance and provided with a row of substantially circular apertures the centres of which lie on a line spaced substantially equidistantly from the opposed longitudinal edges of said strip and the centres of adjacent apertures of which are spaced from each other by a distance substantially equal to said predetermined distance, every other aperture in said row being of said one size and the remaining apertures being of said larger size, said strip being arranged on and connected to said one flange of said member with at least one aperture of said strip 10 of each size being in register with an aperture of corresponding size in said one flange of said member, and fixing means extending through said apertures in register for connecting the element and the member together.

5. A substantially box-section member comprising a longitudinally extending first flange having a width substantially equal to five times a predetermined distance and formed with four rows of substantially circular apertures having their centres on lines spaced from each other by said predetermined distance, the centres of the apertures in the two outer rows being spaced from the adjacent longitudinal edge of said first flange by a distance substantially equal to said predetermined distance and the centres of adjacent apertures in each of said outer rows being spaced from each other by a distance substantially equal to said predetermined distance and the apertures in said outer rows being of one size and having a diameter substantially equal to one-half said predetermined distance, the centres of adjacent apertures in the inner rows being spaced from each other by a distance substantially equal to twice said predetermined distance and the apertures in the inner rows being of a larger size and having a diameter greater than one-half said predetermined distance and not greater than twothirds said predetermined distance, longitudinally extendiug second and third flanges integrally joined to the respective longitudinal edges of the first flange and extending substantially normal to the latter both in the same direction, the second and third flanges having a width substantially equal to three times said predetermined distance and being each formed with two rows of substantially circular apertures, the centres of the apertures in one row of which lie on a line spaced from the adjacent longitudinal edge of the first flange by a distance substantially equal to said predetermined distance and the centres of adjacent apertures in this row being spaced apart by a distance substantially equal to said predetermined distance, these apertures being of said one size and the centres of the apertures in the other row of which lie on a line spaced from the adjacent longitudinal edge of the first flange by a distance substantially equal to twice said predetermined distance, the centres of adjaceut apertures in this row being spaced from each other by a distance substantially equal to twice said predetermined distance, these apertures being of the larger size, and an inturned flange formed on each of the second and third flanges and extending substantially normal to the latter and towards each other substantially parallel to said one flange, each inturned flange being provided with a row of substantially circular apertures every other one of which in a row is of said one size and the remainder thereof being of said larger size, the centres of the apertures in a row in each inturned flange lying on a line parallel to the adjacent longitudinal edge of the second or third flange and spaced therefrom by a distance substantially equal to said predetermined distance and the spacing between the centres of adjacent apertures in these rows being substantially equal to said predetermined distance.

References Cited in the file of this patent UNITED STATES PATENTS 2,022,255 Scott Nov. 26, 1935 2,746,780 Comino May 22, 1956 2,784,812 Kindrof Mar. 12, 1957 FOREIGN PATENTS 153,973 Great Britain Nov. 19, 1920 763,214 Great Britain Dec. 12, 1956 1,118,796 France Mar. 26, 1956 

